Circuit interrupter with locking provision



J1me 1967 N. s. PHILLIPSON 3,327,075

CIRCUIT INTBRRUPTER WITH LOCKING PROVISION Filed 001;. 29, 1964 INVENTOR Neil S- Phillipson BY ATTORNEY United States Patent 3,327,075 CIRCUIT INTERRUPTER WITH LOCKING PROVISION Neil S. Phillipson, Fremont, Califl, assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Filed Oct. 29, 1964, Ser. No. 407,232 Claims. (Cl. 200-42) This invention relates generally to circuit interrupters and more particularly to circuit interrupters of the type that may be padlocked in one or more selected operating positions.

At certain installations it is desirable to be able to padlock a circuit interrupter in one or more selected positions. For certain types of circuit interrupters, the padlocking provision is required or desirable in only a small percentage of the overall number of circuit interrupters that a manufacturer may supply. Thus, it is desirable to provide means for padlocking a standard type circuit interrupter without necessitating substantial reconstruction of the circuit interrupter.

Accordingly, an object of this invention is to provide an improved circuit interrupter having provision for padlocking the actuating handle of the circuit interrupter in one or more selected positions.

Another object of this invention is to provide improved means for padlocking a manually operable handle of a circuit interrupter in on" and ed positions.

Another object of this invention is to provide an improved standard type molded-case circuit interrupter with improved padlocking means permitting the circuit interrupter to be padlocked in one or more selected positions, which padlocking means is readily adaptable to a number of standard types of circuit interrupters without requiring substantial retooling of the interrupters.

Another object of this invention is to provide an improved standard molded-case type circuit interrupter with improved padlocking means that is readily secured to the circuit interrupter, which padlocking means when once secured to the circuit interrupter may be removed only by destruction of the padlocking means or by disassembly of the circuit interrupter.

Another object of this invention is to provide an improved circuit interrupter handle padlocking structure which is simple in construction and economical to manutacture and which may be readily installed in the field. The invention, both as to structure and operation, together with additional objects and advantages thereof, will be best understood from the following detailed description when read in conjunction with the accompanying drawings.

In said drawings:

FIGURE 1 is a sectional view through the center pole of a three-pole circuit breaker embodying principles of this invention;

FIG. 2 is an elevational view of a padlocking device constructed in accordance with principles of this invention;

FIG. 3 is a partial plan view of the circuit breaker of FIG. 1 with the padlocking device of FIG. 2 in a temporary intermediate position that is reached during the operation of attaching the padlocking device to the circuit breaker;

' FIG. 4 is a view similar to FIG. 3 with the padlocking device in the fully attached position;

FIG. 5 is a partial view of part of the breaker seen in FIG. 1 with the padlocking device secured thereto and with a padlock attached to the padlocking device to lock the operating handle in the off position; and

FIG. 6 is a view similar to FIG. 5 with the operating handle locked in the on position.

3,327,375 Patented June 20, 1967 The circuit breaker disclosed in FIG. 1 is more specifically described in the patent to E. J. Walker et al. Pat. No. 3,103,565. Thus, only a brief description of the circuit breaker is given herein.

The circuit breaker 3 disclosed .in FIG. 1 comprises an insulating housing structure comprising a molded insulating base 5 and a molded insulating cover 7. The circuit breaker is a three-pole circuit breaker with a single operating mechanism in the center pole, which center pole is disclosed in FIG. 1. In each pole unit of the circuit breaker there is a stationary contact 9 that is connected to an end terminal conductor 11 by means of a conductor 13, and a movable contact 15 that is secured to a contact arm 17 and electrically connected to a terminal connector 19 by means of a flexible conductor 21, a conductor 23, a conducting coil 25 and a conductor 27.

A single operating mechanism 31, in the center pole unit, is connected to operate the contact arm 17 in the center pole unit. A tie bar 33, which is connected to the contact arm 17, is common to all three pole units. Each of the two outer contact arms 17 is secured to the tie bar 33 so that movement of the contact arm 17 in the center pole unit operates through the tie bar 33 to simultaneously move the contact arms in all three pole units. A toggle link 35 is connected to the contact arm 17 by means of a pivot pin 37. A toggle link 39 is connected to a trip member 41 by means of a pivot pin 43. The toggle links 35 and 39 are pivotally connected by means of a knee pivot pin 45. An inverted U-shaped operating lever 47 is pivotally supported at the ends of the legs thereof on a stationary pivot in a manner well known in the art. Overcenter springs 49 are connected under tension at one end to the upper bight portion of the operating lever 47 and at the other end to a support 51 that is connected to the pivot pin 45. A handle structure 55, comprising an insulating shield part 57 that is molded integral with an insulating handle part 59, is fixedly secured to the upper bight portion of the operating lever 47. The front of the housing cover 7 is formed with an opening 61 therein. The handle part 59 of the handle structure 55 protrudes out through the opening 61 at the front of the housing and the shield part 57 substantially closes the opening 61 in all positions of the handle structure 55. The circuit breaker is manually operated to the on position by clock-wise pivoting movement of the handle structure 55 from the off to the on position during which movement the line of action of the springs 49 is carried to the right to straighten the toggle 39, 35 thereby forcing the movable contact arm structure 17 to move in a clockwise (FIG. 1) closing direction. This movement pivots the tie bar 33, that is rotatably secured on the inner side walls of the circuit breaker housing, to thereby simultaneously move all of the contact arms 17 of the three pole units to move all three contacts 15 into engagement with the associated stationary contacts 9. The circuit breaker is manually operated to the off position by movement of the handle structure 55 from the on to the cit position during which movement the springs 49 are moved overcenter to collapse the toggle 35, 39 moving the movable contact arm 17 for the center pole unit to the open position seen 1 in FIG. 1 during which movement the tie bar 33 is ID- tated to simultaneously move all of the movable contact arms of the three pole units to the open position.

The trip member 41, which is pivotally supported on suitable brackets by means of a pivot pin 65, is latched in the position seen in FIG. 1 by means of a first latch member 67. The first latch member engages the periphery of a rod part 70 of a latch member 69. The first latch member 67 is thereby latched in position by means of a second latch member 69. When an overload occurs in the center pole unit, the coil 25 energizes a magnet member 71 to attract one end of an armature 73 that is pivotally supported intermediate its ends. The other end of the armature 73 engages the second latch member 69 to move the member 69 and rotate the rod part 78 in a clockwise (FIG. 1) direction. During this movement part of the first latch member 67 snaps into a notch (not shown) in the rod 70 to turn unlatch trip member 41 whereupon the springs 49 operate to rotate'the trip member 41- about the pivot 65 to change the line of action of the springs 49 to collapse the toggle 35, 39 to move the movable contact arm 17 of the center pole unit to the open position to thereby move all three contact arms to the open position.

During the tripping operation the handle structure 55 is moved in a manner well known in the art to a tripped position intermediate the off and on positions thereby giving a visual indication that a tripping operation has occurred. The circuit breaker is trip-free in that even though the handle structure 55 is manually held or locked in the on position the circuit breaker mechanism will be operated to the tripped position upon the/occurrence of a tripping overload current.

Before the contacts can be closed following an automatic opening operation, it is necessary to reset and relatch the mechanism. This is accomplished by moving the handle structure 55 counterclockwise to the extreme of? position. During this movement, the handle structure engages the trip member 41 to move the trip member 41 about the pivot 65 to effect a relatching and resetting of parts. Thereafter, the circuit breaker can be manually'operated in the same manner hereinbefore described.

In each pole unit adjusting means indicated generally at 77 is provided in order to effect adjustment of the electromagnetic trip means. There is a similar electromagnetic trip means in each pole unit. The rod 70 is common to all three pole units and a separate latch member, serving the same latching and tripping function of the latch member 69, is secured to the rod 70 in each of the two outer pole units to be engaged by the associated separate armature 73 so that the member 79 is rotated to the tripped position upon the operation of any of the armatures 73 in any of the three pole units.

The shield part 57 of the molded insulating handle structure 55 comprises an arcuate front surface 81 that moves just under the arcuate inner surface 83 of the front part of the cover 7 when the handle structure 55 is pivoted between the on and off positions. The shield part 57, therefore, closes the opening 61 in all positions of the operating handle structure 55.

Referring to FIG. 2, there is shown a padlocking device indicated generally at 85 and comprising a fiat sheet-metal steel member having a main body part 87 and two legs 89 and 91 extending from the main body part 87. The under end 93 of the locking device 85 is an arcuate surface and the upper ends of each of the legs 89 and 91 are arcuate in order to fit within an arcuate passage (FIG. 1) defined by the arcuate shield part 57 and the arcuate surface 83 of the cover 7. The main body part 87 of the locking device 85 is formed with a padlock-receiving opening 95 therein.

The generally rectangular opening 61 in the insulating housing part 7 is defined by two side walls '97 and two end Walls 99. The width of the opening 61, the width of the handle part 59 and the thickness of the locking device are such that the locking device 85 will fit snugly between the handle part 59 and associated side wall 97 at each of the two opposite sides of the handle part 59.

In order to mount the padlocking device 85 to the circuit breaker 3, a worker first bends one leg, for example the leg 91, to position the leg along a plane that is generally normal to the plane of the main body part 87 (FIG. 3). The other leg (89 in FIG. 3) is then inserted at the front of the breaker between the shield part 57 of the handle structure 55 and the arcuate undersurface 83 of the sensing part 7 (FIG. 3). Thereafter, a worker with a tool such, for example, as a small screwdriver presses 4 against the leg 91 straightening the leg 91 during which movement the leg 91 moves between the arcuate shield part 57 of the handle structure 55 and the arcuate surface 83 of the housing part7 to the position disclosed in FIGS. 4-6. With the locking device 85 in the position disclosed in FIGS. 46, the main body part 85 is prevented from moving widthwise in the opening 61 by the engagement of one fiat side of the main body part 87 of the locking device 85 with one of the side walls 97 and by engagement of the other flat side of the main body part '87 with the handle part 59. The locking device 85 is prevented from moving lengthwise in the opening 61 by the engagement of the end parts of the main body part 87 with the end walls 99 (FIGS. 4 6). The locking device 85 is prevented from moving inward by the engagement of the undersurface 93 (FIG. 2) with the shield part 57 of the handle structure 55, and the locking device is prevented from moving outward by the engagement of the leg parts 89 and 91 thereof with the undersurface 83 of the housing part 7. Thus, the locking device 85 is captured in the position disclosed in FIGS. 4-6.

As was previously described, the leg 91 is straightened into the position seen in FIGS. 4-6 by means of a tool such, for example, as a small screwdriver that can be used to push the leg 91 from the bent position seenin FIG. 3 to the straightened position seen in FIG. 4. As

can be seen in FIGS. 4-6, it can be understood that once the leg 91 has, been straightened to the mounted position seen therein, the screwdriver cannot be readily used in order to bend the leg .91 back to the position disclosed in FIG. 3. It is to be noted also that the leg 91 is not readily accessible. for other tools so that the locking device is fixedly secured to the circuit breaker, and it may not be readily removed without the use of a special instrument such as a cutting tool that can bowed to cut the member 85 to thereby permit'removal of the member 85 in two pieces.

The hereinbefore set forth mounting operation of the locking device 85 was accomplished by means of operations bending and straightening the leg 91. It can be understood that either of the legs 89 or 91 could be bent and straightened in the same manner hereinbefore described during a mounting operation .of the locking de-.

vice 85. Moreover, in certain applications, it may be de sirable and practical to bend and straighten both of the legs during the mounting operation.

Referring to FIGS. 5 and 6, it will be noted that when the handle structure 55 is in the off position the hasp 103 of a padlock may be passed through the opening 95 in order to padlock the handle 59 in the foif position, and when the handle structure 55 is in the n position the padlock hasp 103 can be passed. through the opening 95 in order to padlock the handle structure in the on position. The length of the main body portion 87 of the locking device '85 is substantially the length of the-opening 61 in the housing 7 to thereby prevent substantial lengthwise movement of the locking device 85 in the opening 61.

Although in the specifically described embodiment the padlocking device 85 is described as being a sheet metal steel member, it can be understood that an insulating member may be used so long as at least one leg of the member can be deformed into the bent position seen in FIG. 3 and then straightened into the straightened position seen in FIG. 4 during the mounting and operation of the locking device 85. The padlocking device may also comprise a member having such resilience or spring characteristics that the one leg thereof may be bent and held in the bent (FIG. 3) position during the first step of the mounting operation which member will automatically spring back to the straightened (FIGS. 4-6) mounted position when released.

From the foregoing, it can be understood that there is provided by this invention a simple and efiicient means for locking the handle of a circuit interrupter in one or more selected positions. The improved padlocking device can be readily mounted on a standard type of moldedcase circuit breaker at either of two opposite sides of the circuit breaker operating handle. Once the padlocking device is mounted in position on the circuit breaker it cannot be readily removed from the circuit breaker without the use of a special tool such as a cutting tool. Thus, a worker can have increased confidence that the circuit breaker will remain in the padlocked position.

Since numerous changes may be made in the abovedescribed construction and because different embodiments of the invention may be made without departing from the spirit and scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

1. A circuit interrupter comprising -a housing having an opening therein, a handle structure supported in proximity to said opening and comprising a handle part extending from said opening, a circuit-interrupter mechanism supported within said housing and comprising a pair of cooperable contacts, said handle structure being movable between two operating positions to open and close said contacts, a one-piece locking device in said opening captured in a fixed position between said handle structure and said housing, said handle structure being movable between said two operating positions with said locking device in said fixed position, said locking device comprising means for receiving the hasp of a padlock to lock said handle structure in either of said positions.

2. A circuit breaker comprising an insulating housing having an opening at the front thereof, a circuit-breaker mechanism supported within said housing and comprising a pair of contacts, a handle structure supported in proximity to said opening and comprising a shield part supported generally within said housing at said opening and a handle part extending from said shield part through said opening, said handle structure being movable between two positions to open and close said contacts, said shield part closing said opening in all positions of said handle structure, said housing comprising spaced ledges at opposite sides of said opening, a one-piece locking member in a fixed position in said opening fixedly supported between said shield part and said housing and comprising opposite legs supported between said shield part and said ledges, said handle structure being movable between said two positions with said one-piece locking member in said fixed position, said one-piece locking member having opening means therein for receiving the hasp of a padlock to prevent movement of said handle structure from one to the other of said positions.

3. A circuit breaker comprising an insulating housing having an opening at the front thereof, said housing comprising two opposite side walls and two opposite end walls defining said opening, a circuit-breaker mechanism supported within said housing and comprising a pair of contacts, a handle structure supported in proximity to said opening and comprising a shield part supported generally within said housing at said opening and a handle part extending from said shield part outward through said opening, said handle structure being movable between two positions to open and close said contacts, a locking device comprising a one-piece generally flat sheet-material member having a main body part and two leg parts, said generally flat sheet-material member being fixedly supported on said circuit breaker in said opening with said leg parts being disposed under said end walls and with said main body part being supported between said handle part and one of said side walls, said generally fiat sheet-material member comprising at least one deformable leg part to enable said leg part to be first bent into a plane that is generally normal to a plane of a flat side of said generally flat sheet-material member and then generally straightened to a fully mounted fixed position under one of said end walls, said handle structure being movable between said two positions with said generally fiat sheet-material member in said fully mounted fixed position, and said mean body part having opening means therein for receiving the hasp of a padlock to prevent movement of said handle structure from one to the other of said positions.

4. A circuit breaker comprising an insulating housing having an opening at the front thereof, said housing comprising two opposite side walls and two opposite end walls defining said opening, a circuit-breaker mechanism supported within said housing and comprising a pair of contacts, a handle structure supported in proximity to said opening and comprising a shield part supported generally within said housing at said opening and a handle part extending from said shield part outward through said opening, said handle structure being movable between two positions to open and close said contacts, a locking device comprising a one-piece generally fiat sheetmaterial member having a main body part and two leg parts, said generally flat sheet-material member being supported in a fixed position on said circuit breaker in said opening with said leg parts being disposed under said end walls and with said main body part being disposed between said handle part and one of said side walls, said main body part having opening means therein for receiving the hasp of a padlock, said generally flat sheetmaterial member engaging said handle part and said one side wvall to prevent substantial movement of said generally flat sheet-material member along a plane that is generally normal to a plane of a flat side of said generally fiat sheet-material member, said generally flat sheet-material engaging said shield part to prevent movement of said generally flat sheet-material member inward through said opening, said leg parts engaging said housing to prevent movement of said generally fiat sheet-material member outward through said opening, and said handle structure being movable between said two positions with said generally flat sheet-material member in said fixed position.

5. A circuit breaker comprising an insulating housing having an opening at the front thereof, said insulating housing comprising two opposite end walls and two opposite side walls defining said opening, a circuit breaker mechanism supported within said housing and comprising a pair of contacts, a handle structure su ported in proximity to said opening and comprising a shield part supported generally within said housing at said opening .and a handle part extending from said shield part outward through said opening, said shield part having an arcuate surface at the front thereof, said insulating housing having an internal arcuate surface in proximity to said opening opposite said front arcuate surface of said shield part to thereby form an arcuate passage between said shield part and said housing, a locking device comprising a onepiece generally fiat sheet-material member having an arcuate internal end part engaging said arcuate front surface of said shield part, said generally fiat sheet-material member comprising a main body part and two opposite leg parts and being supported on said circuit breaker in said opening in a fixed position with said opposite leg parts being disposed under said opposite end walls in said arcuate passage and with said main body part being positioned between said handle part said one side wall and said two end walls whereby said member is captured against removal between said handle structure and said housing, said handle structure being movable between two positions to open and close said contacts while said generally flat sheet-material member remains in said fixed position, said generally flat sheet-material member comprising means for receiving the hasp of a padlock to prevent movement of said handle structure from one to the other of said positions.

(References on following page) 7 8 References Cited 3,055,995 9/ 1962 Snow 200-42 X UNITED STATES PATENTS I 3,076,876 2/1963 stal'lback gt a1. 200-42X 'j 2,849,552 8/1958 Firestone 20042 ROBERT K. SCHAFFER, Primary Examiner.

2,943,162 6/1960 Norden 20042X 5 9 3 7 9 5 19 osieja et 1 44 X R. S. MACON, H. HOHAUSER, Assistant Examiners. 

1. A CIRCUIT INTERRUPTER COMPRISING A HOUSING HAVING AN OPENING THEREIN, A HANDLE STRUCTURE SUPPORTED IN PROXIMITY TO SAID OPENING AND COMPRISING A HANDLE PART EXTENDING FROM SAID OPENING, A CIRCUIT-INTERRUPTER MECHANISM SUPPORTED WITHIN SAID HOUSING AND COMPRISING A PAIR OF COOPERABLE CONTACTS, SAID HANDLE STRUCTURE BEING MOVABLE BETWEEN TWO OPERATING POSITIONS TO OPEN AND CLOSE SAID CONTACTS, A ONE-PIECE LOCKING DEVICE IN SAID OPENING CAPTURED IN A FIXED POSITION BETWEEN SAID HANDLE STRUCTURE AND SAID HOUSING, SAID HANDLE STRUCTURE BEING MOVABLE BETWEEN SAID TWO OPERATING POSITIONS WITH SAID LOCKING DEVICE IN SAID FIXED POSITION, SAID LOCKING DEVICE COMPRISING MEANS FOR RECEIVING THE HASP OF A PADLOCK TO LOCK SAID HANDLE STRUCTURE IN EITHER OF SAID POSITIONS. 